We believe that 96% of the mass and energy content of our Universe is invisible. Some is in the form of Dark Matter whose presence we can only detect by its gravitational influence.
The majority, called Dark Energy, appears to be ripping our Universe apart- Gresham College
Bio
Ian Morison
Gresham Professor of Astronomy Ian Morison made his first telescope at the age of 12 with lenses given to him by his optician. Having studied Physics, Maths and Astronomy at Oxford, he became a radio astronomer at the Jodrell Bank Observatory and teaches Astronomy and Cosmology at the University of Manchester.
Over 25 years he has also taught Observational Astronomy to many hundreds of adult students in the North West of England. An active amateur optical astronomer, he is a council member and past president of the Society for Popular Astronomy in the United Kingdom.
At Jodrell Bank he was a designer of the 217 KM MERLIN array and has coordinated the Project Phoenix SETI Observations using the Lovell Radio Telescope. He contributes astronomy articles and reviews for New Scientist and Astronomy Now, and produces a monthly sky guide on the Observatory's website.
Nonluminous matter not directly detectable by astronomers, hypothesized to exist because the mass of the visible matter in the universe cannot account for observed gravitational effects. Dark matter comes in two varieties: baryonic, which is about 5 percent of the universe, and nonbaryonic, which is 22 percent of the universe. The nonbaryonic dark matter is believed to consist of heavy, electromagnetically neutral particles called weakly interacting massive particles (WIMPs).
The dominant component (about 70 percent) of the universe. Its nature is not well understood, but it differs from matter in being gravitationally repulsive. Dark energy is detected by its effect on the rate at which the universe expands. Many explanations have been proposed for dark energy; the simplest is that it is an energy density inherent to empty space.
This lecture was extremely informative and very fascinating. I have been doing some research on Dark Matter and Dark Energy and have been looking for a source that clearly spells out what it's all about, without all the complicated mathematics and scientific jargon. Thank you so much Ian Morrison and Fora tv, this was exactly what I was looking for and have learned a great deal!
member. 
